Propulsion mechanism for endoscopic systems

ABSTRACT

A self propelled, endoscopic apparatus formed of a flexible, fluid-filled toroid and a motorized or powerable frame The apparatus may be used to advance a variety of accessory devices into generally tubular spaces and environments for medical and non-medical applications. The apparatus when inserted into a tubular space or environment, such as the colon of a patient undergoing a colonoscopy, is advanced by the motion of the toroid. The toroid&#39;s surface circulates around itself in a continuous motion from inside its central cavity along its central axis to the outside where its surface travels in the opposite direction until it again rotates into its central cavity. As the device advances within the varying sizes, shapes and contours of body lumens, the toroid compresses and expands to accommodate and navigate the environment. The motion of the toroid can be powered or unpowered and the direction and speed may be controlled. The apparatus may be used to transport a variety of accessory devices to desired locations within tubular spaces and environments where medical and non-medical procedures may be performed.

RELATED APPLICATIONS

[0001] The present application claims the benefit of U.S. ProvisionalPatent Application, Serial No. 60/462,787, filed Apr. 14, 2003. Theentire disclosure of the above-mentioned application is herebyincorporated by reference.

FIELD OF THE INVENTION

[0002] This invention relates to an apparatus useful in medical andnon-medical applications to introduce accessory devices into collapsibleand non-collapsible, body cavities or canals, pipes, lumens and othergenerally tubular spaces or environments. More particularly, theinvention relates to a propulsion system for endoscopic systems.

BACKGROUND OF THE INVENTION

[0003] An endoscope is any instrument used to obtain a view of theinterior of a patient's body using a variety of means to capture andtransmit the view to an observer. Endoscopes can also be used to performa variety of diagnostic and interventional procedures such as biopsiesand other small surgical procedures. Examples of endoscopes include: acolonoscope used within the colon, a gastroscope used inside thestomach, and a bronchoscope used within the trachea and bronchi.Endoscopes are often inserted into body cavities or lumens via naturalorifices but can also be inserted into incisions to gain access to areasof the body where no natural entrance exists.

[0004] Traditional endoscopes consist of a rigid or flexible rod orshaft with a means of collecting and transmitting an image from insidethe patient's body. The rod or shaft is inserted and pushed to thelocation of interest. The rod or shaft typically surrounds a number ofpathways used to house fiber optic cables and route instruments,catheters, devices, gasses, liquids and other substances in and out ofthe area of interest.

[0005] Traditional endoscopes require a minimal rigidity for successfulinsertion and work well when the body cavity or canal, or other lumenshaving curves and turns. However, when it is constricted, convoluted andconsists of many curves, as is the case with the colon, it can bedifficult or impossible to push the endoscope to its desired location.Steerable articulating endoscopes are often used to make navigation ofturns easier; however, the increased friction associated with eachadditional turn limits the number of turns that can be navigatedsuccessfully and ultimately limits the distance an endoscope can beintroduced into the patient's body. In addition, the increased forcerequired to complete more turns and corners raises the risk ofcomplications such as bowel perforation as well as the discomfort andpain experienced by the patient. It would be useful to have an apparatusfor endoscopic medical procedures that can navigate in such environmentsand can overcome the physical and procedural limitation of traditionalendoscopes. It would further be useful if such an apparatus wereself-propelled.

[0006] Endoscopic devices may also be utilized in non-medical orcommercial and industrial applications to obtain views from or introduceinstruments or devices into generally tubular spaces or environmentssuch as lumens, sections of pipe or other structures, which may have anumber of curves and turns. Such tubular spaces or environments may bepartially occluded or have buildup on their interior surfaces and thuspresent a irregular internal shape or diameter. To navigate through suchspaces and environments, it would be useful to have a device orapparatus that can adapt to the internal shape or diameter of the spaceor environment into which it is introduced and of further use if theapparatus were self-propelled.

SUMMARY OF THE INVENTION

[0007] The invention in it various embodiments is a propulsion apparatusthat can be used to transport accessory devices within body cavities orcanals, sections of pipe, lumens, and other generally tubular spaces andenvironments and is generally comprised of a toroid and a powered ormotorized frame. The motion of the toroid can be powered or unpoweredand the direction and speed may be controlled.

[0008] In an embodiment of the invention, the apparatus is comprised ofa toroid and a frame. The toroid is a fluid-filled, enclosed ring formedof a flexible material. The enclosed ring defines a central cavity,having an interior volume and presenting an exterior surface and aninterior surface which move continuously in opposite directions when theapparatus is in motion.

[0009] In one embodiment, the frame is formed of a support structure, ahousing structure and a series of at least two sets of interlockingrollers or skids located on the support and housing structures. Thesupport structure is located within the interior volume of the enclosedring. The housing structure is concentrically and coaxially locatedrelative to the support structure and disposed in the central cavity ofthe enclosed ring. The rollers or skids are located so as to maintainthe two structures in a fixed spatial relationship with the flexiblematerial of the enclosed ring being positioned between the twostructures and the rollers or skids located thereon.

[0010] In another embodiment, the frame is formed of a support structurelocated within the interior volume of the enclosed ring and a series ofat least two sets of interlocking rollers or skids located on thesupport structure. The rollers or skids are located so as to maintainthe flexible material of the enclosed ring between them.

[0011] In other embodiments of the invention, the apparatus is apropulsion apparatus for transport of accessory devices. The apparatusis comprised of a toroid and a powered frame. The toroid is afluid-filled, enclosed ring formed of a flexible material. The enclosedring defines a central cavity and has an interior volume. The poweredframe is formed of a support structure and housing structure or asupport structure alone. A series of at least two sets of interlockingrollers or skids located on the support and housing structures or on thesupport structure in the case there is no housing structure. The supportstructure is located within the interior volume of the enclosed ring.The housing structure is concentrically and coaxially located relativeto the support structure and disposed within the central cavity of theenclosed ring. The rollers or skids are located so as to maintain thetwo structures in a fixed spatial relationship with the flexiblematerial of the enclosed ring being positioned between the twostructures and the rollers or skids located thereon. The rollers may beconnected to a power source and when powered provides a motive,directional force to the flexible material.

[0012] In its various embodiments, the apparatus of the invention mayfurther comprise at least one accessory device. Depending upon whetherthe apparatus is to be used for medical or non-medical applications, theat least one accessory device may be selected from the group consistingof endoscopes, cameras, video processing circuitry, fiber optic cables,electronic communication cables, lasers, surgical instruments, medicalinstruments, diagnostic instruments, instrumentation, sensors, stentcatheters, fluid delivery devices, drug delivery devices, electronicdevices, tools, sampling devices, assay devices, articulating segments,cables to articulate the articulating segments, other accessory devices,and combinations thereof.

[0013] The apparatus of the invention may further comprise a powersource connected to the rollers which when powered provide a motiveforce to the flexible material of the enclosed ring. The power sourcemay be an external power source or an internal power source and may betransmitted through the shaft by various means.

[0014] In its various embodiments, the apparatus of the invention mayfurther comprise an accessory tube. The accessory tube has at least onepathway through which accessory devices can be inserted into the patientor connected to external supporting devices.

[0015] The apparatus of the invention may be utilized to perform medicalor non-medical procedures. In an embodiment of a procedure according tothe invention, the apparatus is utilized for medical procedures. Theprocedure of this embodiment comprising the steps of: introducing aself-propellable, endoscopic apparatus according to the invention intothe rectum and anal canal of a patient, the apparatus being equippedwith at least one accessory device and connected to at least oneexternal support device; powering the apparatus to propel the apparatusforward through the anal canal and into the colon up to a location inthe colon at which at least one medical procedure is to be performed;performing the at least one medical procedure with the at least oneaccessory device; optionally, serially propelling the apparatus toanother location in the colon at which the at least one medicalprocedure is to be performed and performing said at least one medicalprocedure; propelling the apparatus backward through the colon and intothe anal canal; and removing the apparatus from the patient.

[0016] In another embodiment of the invention, an endoscopic procedureis provided. The endoscopic procedure comprises the steps of:introducing a self-propellable, endoscopic apparatus into the generallytubular space or environment, the apparatus being equipped with at leastone accessory device and connected to at least one external supportdevice; powering the apparatus to propel and navigate the apparatusforward in the tubular space to a location at which at least oneendoscopic procedure is to be performed; performing the at least oneendoscopic procedure with the at least one accessory device; optionally,serially propelling the apparatus to another location in the tubularspace at which the at least one endoscopic procedure is to be performedand performing said at least one endoscopic procedure; propelling theapparatus backward through tubular space; and removing the apparatusfrom the tubular space.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017]FIG. 1 is a sectional view of an apparatus in accordance with anexemplary embodiment of the invention.

[0018]FIG. 2 is a sectional view of an apparatus in accordance with anadditional exemplary embodiment of the invention.

[0019]FIG. 3 is an axial cross-sectional view of an apparatus inaccordance with an exemplary embodiment of the present invention.

[0020]FIG. 4 is an axial cross-sectional view of an apparatus inaccordance with an additional exemplary embodiment of the presentinvention.

[0021]FIG. 5 is an enlarged, partial, cross-sectional view of anapparatus in accordance with an exemplary embodiment of the invention.

[0022]FIG. 6 is an enlarged, partial, cross-sectional view of anapparatus in accordance with an exemplary embodiment of the invention.

[0023]FIG. 7 is an enlarged, partial, cross-sectional view of anapparatus in accordance with an additional exemplary embodiment of theinvention.

[0024]FIG. 8 is an enlarged, partial, cross-sectional view of anapparatus in accordance with an exemplary embodiment of the invention.

[0025]FIG. 9 is an enlarged, partial cross-sectional view of anapparatus in accordance with an additional exemplary embodiment of theinvention.

[0026]FIG. 10 is an additional enlarged, partial cross-sectional view ofthe apparatus shown in the previous figure.

[0027]FIG. 11 is an enlarged, partial, cross-sectional view of anapparatus in accordance with an exemplary embodiment of the invention.

[0028]FIG. 12 is an additional enlarged, partial cross-sectional view ofthe apparatus shown in the previous figure.

[0029]FIG. 13 is an enlarged, partial cross-sectional view of anapparatus in accordance with an additional exemplary embodiment of thepresent invention.

[0030]FIG. 14 is a cross-sectional view of a bladder in accordance withan exemplary embodiment of the present invention.

[0031]FIG. 15 is an additional cross-sectional view of bladder shown inthe previous figure.

DETAILED DESCRIPTION OF THE INVENTION

[0032] The self-propellable or self-propelled endoscopic system orapparatus of the invention can be utilized to transport a variety ofaccessory devices to desired locations within a number of generallytubular spaces and environments, both collapsible and non-collapsible,for medical, industrial and commercial applications. With the system ofthe invention, an operator, such as a doctor, medical or othertechnician, can navigate and traverse within generally tubular spacesand/or environments whether of standard or non-standard dimensionsand/or of uniform or non-uniform quality that cause difficulty whennavigated by pushing a rod or “snake” through it. Examples of suchspaces or environments would include, but are not limited to a circular,square, rectangular, or other shaped tube or a tube presenting one ormore such shapes along its length that is partially occluded or interiorsurface of which is irregular, possibly due to material buildup on thesurface. And may further include a route with varying diameters,constrictions and curves.

[0033]FIG. 1 is a sectional view of an apparatus 100 in accordance withan exemplary embodiment of the invention. With reference to FIG. I itwill be appreciated that the system or apparatus 100 of the inventionemploys a toroid 102. In the embodiment of FIG. 1, the toroid 102comprises a bladder 104 of a flexible material 106. The flexiblematerial 106 of bladder 104 has an interior surface 120 and an exteriorsurface 122. Interior surface 120 of flexible material 106 defines aninterior volume 124 of bladder 104. In some embodiments of the presentinvention, interior volume 124 of bladder 104 contains or is filled witha fluid, a gas, liquid or combination thereof. Exterior surface 122 offlexible material 106 defines a central cavity 126.

[0034] The apparatus 100 shown in FIG. 1 also includes a frame 108.Frame 108 both supports and interacts with flexible material 106 ofbladder 104. Frame 108 is formed of a support structure 128 and ahousing structure 130. With reference to FIG. 1, it will be appreciatedthat housing structure 130 is disposed in central cavity 126 defined byexterior surface 122 of flexible material 106 of bladder 104. Also withreference to FIG. 1, it will be appreciated that support structure 128is disposed within interior volume 124 defined by interior surface 120of flexible material 106 of bladder 104.

[0035] Support structure 128 and housing structure 130 each rotatablysupport a plurality of rollers. In FIG. 1, a pair of motive rollers 134are shown contacting flexible material 106 of bladder 104. In theembodiment of FIG. 1, rotation of motive rollers 134 will cause flexiblematerial 106 to move relative to the rotational axis of each motiveroller 134. In the embodiment of FIG. 1, each motive roller 134comprises a plurality of teeth 140. With reference to FIG. 1, it will beappreciated that the teeth 140 of each motive roller 134 mate with afirst thread 142 of a worm gear 144. Accordingly, in the embodiment ofFIG. 1, rotation of worm gear 144 will cause motive rollers 134 torotate.

[0036] The power for rotating motive rollers 134 can be any of a varietyof internal or external power sources known to those skilled in the artto be suitable for the given application. In the case of electricalpower, the power source may be stored inside the apparatus, or the powermay be transmitted via wires from outside the patient or space throughan accessory tube (not shown) connected to the apparatus or to one ormore electrical motors located inside the housing structure or otherwiseoperatively connected to motive rollers 134 and/or worm gear 144. Theelectrical motors, in turn, power the motive rollers 134 and/or wormgear 144. In the case of mechanical power, rollers 134 and/or worm gear144 may be powered by a thin, flexible, spinning rod or wire poweredfrom a remote motor located outside the patient or space. The motion ofthe rod or wire is transmitted to the rollers located on the housingstructure. Mechanical power may also be transmitted by a spinning spiralor spring component located inside or outside of the apparatus. Thispower may be manually generated.

[0037] In the embodiment of FIG. 1, housing structure 130 rotatablysupports a plurality of stabilizing rollers 136. With reference to FIG.1, it will be appreciated that each stabilizing roller 136 contactsexterior surface 122 of flexible material 106 of bladder 104. In theembodiment of FIG. 1, a suspended stabilizing roller 138 is locatedproximate each stabilizing roller 136. Each suspended stabilizing roller138 contacts interior surface 120 of flexible material 106 of bladder104. In the embodiment of FIG. 1, each suspended stabilizing roller 138defines a groove 146 that is dimensioned to receive a portion offlexible material 106 and a portion of a stabilizing roller 136.

[0038] In the embodiment of FIG. 1, each suspended stabilizing roller138 is pivotally coupled to an arm 148. In some useful embodiments ofthe present invention, each arm 148 and suspended stabilizing roller 138act to bias exterior surface 122 of flexible material 106 against astabilizing roller 136. Also in FIG. 1, a plurality of suspended motiverollers 132 are disposed proximate each motive roller 134. Eachsuspended motive roller 132 is pivotally supported by support structure128. In some useful embodiments of the present invention, supportstructure 128 and suspended motive rollers 132 act to bias exteriorsurface 122 of flexible material 106 against motive rollers 134.

[0039] For some applications, bladder 104 may be generally longer thanit is wide. However, for other applications or depending upon the sizeor dimension of the space or environment into which the toroid 102 is tobe introduced, the bladder 104 may be of substantially equal length andwidth or may be wider than it is long.

[0040]FIG. 2 is a sectional view of an apparatus 200 in accordance withan additional exemplary embodiment of the invention. With reference toFIG. 2 it will be appreciated that apparatus 200 comprises a bladder 204that is generally toroidal or ring shaped. Bladder 204 comprises aflexible material 206. Flexible material 206 of bladder 204 has aninterior surface 220 and an exterior surface 222. Interior surface 220of flexible material 206 defines an interior volume 224 of bladder 204.In some embodiments of the present invention, interior volume 224 ofbladder 204 contains or is filled with a fluid, a gas, liquid orcombination thereof. Exterior surface 222 of flexible material 206defines a central cavity 226.

[0041] The apparatus 200 shown in FIG. 2 also includes a frame 208.Frame 208 both supports and interacts with the flexible material 206 ofthe bladder 204. Frame 208 comprises a support structure 228 and ahousing structure 230. With reference to FIG. 2, it will be appreciatedthat housing structure 230 is disposed in central cavity 226 defined byexterior surface 222 of flexible material 206 of bladder 204. Also withreference to FIG. 2, it will be appreciated that support structure 228is disposed within interior volume 224 defined by interior surface 220of flexible material 206 of bladder 204.

[0042] Support structure 228 and housing structure 230 each rotatablysupport a plurality of rollers. In FIG. 2, a plurality motive rollers234 are shown contacting flexible material 206 of bladder 204. In theembodiment of FIG. 2, rotation of motive rollers 234 is capable ofcausing flexible material 206 to move relative to the rotational axis ofeach motive roller 234. In the embodiment of FIG. 2, each motive roller234 comprises a plurality of teeth 240. Each motive roller 234 iscapable of mating with a worm gear 244.

[0043] With reference to FIG. 2, it will be appreciated that worm gear244 comprises a first thread 242 and a second thread 243. In FIG. 2, theteeth 240 of a first set of motive roller 234 are shown mating withfirst thread 242 of worm gear 244. Accordingly, in the embodiment ofFIG. 2, rotation of worm gear 244 will cause the first set of motiverollers 234 to rotate.

[0044] In some embodiments of an apparatus in accordance with anexemplary embodiment of the present invention, a one or more motiverollers are powered by a worm gear. A housing structure of the apparatusmay contain a hollow cavity to hold the worm gear in place asillustrated, for example, in FIG. 2. This hollow cavity allows the wormgear 244 to rotate relative to housing structure 230. Worm gear 244 mayalso move forwards and backward along the central axis of the apparatusin the embodiment of FIG. 2. This movement allows second thread 243 ofworm gear 244 to selectively engage a second set of motive rollers whilefirst thread 242 disengages from first set of motive rollers 234. Thisselective engagement may facilitate forwards and backwards movement ofthe apparatus. In a variation of this embodiment, the apparatus may beconfigured so that the first and the second set of motive rollers 234respectively engage first and second threads 242, 243.

[0045] In the embodiment of FIG. 2, housing structure 230 rotatablysupports a plurality of stabilizing rollers 236. With reference to FIG.2, it will be appreciated that each stabilizing roller 236 contacts theexterior surface 222 of flexible material 206 of bladder 204. In theembodiment of FIG. 2, a plurality of suspended stabilizing rollers 238are located proximate each stabilizing roller 236. Each suspendedstabilizing roller 238 contacts interior surface 220 of flexiblematerial 206 of bladder 204. In some useful embodiments of the presentinvention, each suspended stabilizing roller 238 acts to bias exteriorsurface 222 of flexible material 206 against a stabilizing roller 236.

[0046] With continuing reference to FIG. 2, a suspended motive roller232 is disposed proximate each motive roller 234. Each suspended motiveroller 232 is pivotally supported by support structure 228. In someuseful embodiments of the present invention, support structure 228 andsuspended motive rollers 232 act to bias exterior surface 222 offlexible material 206 against motive rollers 234.

[0047] Various embodiments of housing structure 230 and supportstructure 228 are possible without deviating from the spirit and scopeof the present invention. One exemplary embodiment may be viewed as twotubes positioned with one inside the other. The outer tube being thesupport structure which is located within the interior volume of theenclosed ring or bladder. The inner tube being the housing structurewhich is located within the central cavity. In another embodimentexemplary embodiment, either the support structure, the housingstructure or both may be comprised of a series of one or more beams thatmay or may not form the general shape of a cylinder.

[0048] The housing and support structures may be, for example,cylindrical with a circular cross section or they may have a crosssection in the shape of a square, rectangle, triangle, hexagon or anyother shape with straight or curved surfaces or any combination thereof.The frame structures may also be comprised of multiple cross sectionalshapes throughout its length. The flexible material 206 of the bladder204 surface runs between the two tubes which are spaced in fixedrelationship relative to each other. The distance between the two tubesis sufficient to accommodate the interlocking rollers or skids and toallow the flexible material 206 for bladder 204 to pass between thesupport and housing structures even if the material folds over itself oris bunched up.

[0049]FIG. 3 is an axial cross-sectional view of an apparatus 300 inaccordance with an exemplary embodiment of the present invention.Apparatus 300 includes a bladder 304 comprising a flexible material 306.The flexible material 306 of bladder 304 has an interior surface 320 andan exterior surface 322. Interior surface 320 of flexible material 306defines an interior volume 324 of bladder 304. In some embodiments ofthe present invention, interior volume 324 of bladder 304 contains or isfilled with a fluid, a gas, liquid or combination thereof. Exteriorsurface 322 of flexible material 306 defines a central cavity 326.

[0050] In the embodiment of FIG. 3, a housing structure 330 is disposedin central cavity 326 defined by exterior surface 322 of flexiblematerial 306 of bladder 304. The housing structure 330 rotatablysupports a plurality of motive rollers 334. In FIG. 3, motive rollers334 are shown contacting exterior surface 322 of flexible material 306.In the embodiment of FIG. 3, each motive roller 334 comprises aplurality of teeth 340. The teeth 340 of each motive roller 334 matewith a thread 342 of a worm gear 344. Thus, in the embodiment of FIG. 3,rotation of worm gear 344 will cause motive rollers 334 to rotate. Alsoin the embodiment of FIG. 3, rotation of the motive rollers 334 willcause flexible material 306 to move relative to the rotational axis ofeach motive roller 334.

[0051] With continuing reference to FIG. 3, it will be appreciated thata support structure 328 is disposed within an interior volume 324defined by the interior surface 320 of flexible material 306. In theembodiment of FIG. 3, support structure 328 rotatably supports aplurality of suspended motive rollers 332. In FIG. 3, one suspendedmotive roller 332 is shown disposed proximate each motive roller 334.Also in FIG. 3, each suspended motive roller 332 can be seen contactinginterior surface 320 of flexible material 306 of bladder 304. In someuseful embodiments of the present invention, support structure 328 andsuspended motive rollers 332 act to bias exterior surface 322 offlexible material 306 against motive rollers 334.

[0052] In the exemplary embodiment of FIG. 3, housing structure 330 andsupport structure 328 each have a generally tubular shape. Thus, housingstructure 330 and support structure 328 may be viewed as two tubespositioned with one inside the other. The outer tube being supportstructure 328 which is located within interior volume 324 defined byinterior surface 320 of bladder 304. The inner tube being housingstructure 330 which is located within central cavity 326 defined byexterior surface 322 of bladder 304.

[0053] It will be appreciated that various embodiments of housingstructure 330 and support structure 328 are possible without deviatingfrom the spirit and scope of the present invention. The housing andsupport structures may be, for example, cylindrical with a circularcross section or they may have a cross section in the shape of a square,rectangle, triangle, hexagon or any other shape with straight or curvedsurfaces or any combination thereof. The frame structures may also becomprised of multiple cross sectional shapes throughout their length.The flexible material 306 of the bladder 304 surface runs between thetwo structures which are spaced in fixed relationship relative to eachother. The distance between the two structures is sufficient toaccommodate the interlocking rollers or skids and to allow the flexiblematerial 306 for bladder 304 to pass between the support and housingstructures even if the material folds over itself or is bunched Up.

[0054]FIG. 4 is an axial cross-sectional view of an apparatus 400 inaccordance with an additional exemplary embodiment of the presentinvention. Apparatus 400 comprises a bladder 404 of a flexible material406. In FIG. 4 a support structure 428 is shown disposed within aninterior volume 424 defined by the interior surface 420 of flexiblematerial 406. In the embodiment of FIG. 4, support structure 428rotatably supports a plurality of suspended stabilizing rollers 438.With reference to FIG. 4, it will be appreciated that each suspendedstabilizing roller 438 contacts the interior surface 420 of flexiblematerial 406 of bladder 404. In some useful embodiments of the presentinvention, support structure 428 and suspended stabilizing roller 438act to bias exterior surface 422 of flexible material 406 against astabilizing roller 436.

[0055] In the embodiment of FIG. 4, a housing structure 430 is disposedin a central cavity 426 defined by an exterior surface 422 of flexiblematerial 406 of bladder 404. Housing structure 430 rotatably supports aplurality of stabilizing rollers 436. With reference to FIG. 4, it willbe appreciated that each stabilizing roller 436 contacts the interiorsurface 420 of flexible material 406 of bladder 404. In the embodimentof FIG. 4, each suspended stabilizing roller 438 defines a groove 446that is dimensioned to receive a portion of flexible material 406 and aportion of a stabilizing roller 436.

[0056]FIG. 5 is an enlarged, partial, cross-sectional view of anapparatus in accordance with an exemplary embodiment of the invention.Apparatus 500 comprises a housing structure 530 and a support structure528. Housing structure 530 rotatably supports a motive roller 534 andsupport structure 528 rotatably supports a plurality of suspended motiverollers 532. A flexible material 506 is disposed between motive roller534 and suspended motive rollers 532. Flexible material 506 may form,for example, a portion of a bladder in accordance with the presentinvention. Suspended motive rollers 532 are rotatably supported by asupport structure 528. In the embodiment of FIG. 5, housing structure530 rotatably supports a worm gear 544. A first thread 542 of worm gear544 engages teeth 540 of motive roller 534. In the embodiment of FIG. 5,rotation of worm gear 544 will cause motive roller 534 to rotate.Rotation of motive roller 534, in turn, causes flexible material 506 tomove relative to housing structure 530. With reference to FIG. 5, itwill be appreciated that flexible material 506 has an interior surface520 and an exterior surface 522.

[0057]FIG. 6 is an enlarged, partial, cross-sectional view of anapparatus 600 in accordance with an exemplary embodiment of theinvention. Apparatus 600 comprises a housing structure 630 thatrotatably supports a worm gear 644. A first thread 642 of worm gear 644engages the teeth 640 of a motive roller 634. Motive roller 634 isrotatably supported by housing structure 630. A flexible material 606 isdisposed between motive roller 634 and a skid 650. Flexible material 606may form, for example, a portion of a bladder in accordance with thepresent invention.

[0058] In the embodiment of FIG. 6, rotation of worm gear 644 causesrotation of motive roller 634. Rotation of motive roller 634, in turn,causes flexible material 606 to move relative to housing structure 630.With reference to FIG. 6, it will be appreciated that skid 650 contactsan interior surface 620 of flexible material 606. In some usefulembodiments of the present invention, skid 650 acts to bias an exteriorsurface 622 of flexible material 606 against motive roller 634.

[0059]FIG. 7 is an enlarged, partial, cross-sectional view of anapparatus 603 in accordance with an additional exemplary embodiment ofthe invention. Apparatus 603 comprises a housing structure 630 thatrotatably supports a motive roller 634. A flexible material 606 isdisposed between motive roller 634 and a skid 650. In the embodiment ofFIG. 7, a pair of springs 652 act to bias skid 650 against an interiorsurface 620 of flexible material 606. Springs 652 are diagrammaticallyillustrated in FIG. 7. Springs 652 may comprise, for example, sheetmetal arms. A compression motion and an extension motion of springs 652and skid 650 are illustrated with arrows in FIG. 7.

[0060] In some useful embodiments of the present invention, skid 650 andsprings 652 act to bias an exterior surface 622 of flexible material 606against motive roller 634. Teeth 640 of motive roller 634 engage a firstthread 642 of a worm gear 644 that is rotatably supported by housingstructure 630. In the embodiment of FIG. 7, rotation of worm gear 644causes rotation of motive roller 634. Rotation of motive roller 634, inturn, causes flexible material 606 to move relative to housing structure630.

[0061]FIG. 8 is an enlarged, partial, cross-sectional view of anapparatus in accordance with an exemplary embodiment of the invention.Apparatus 700 includes a frame 708 comprising a housing structure 730and a support structure 728. Housing structure 730 rotatably supports amotive roller 734 and support structure 728 rotatably supports aplurality of suspended motive rollers 732. A flexible material 706 isdisposed between motive roller 734 and suspended motive rollers 732.

[0062] Suspended motive rollers 732 are rotatably supported by a supportstructure 728. A pair of springs 752 of support structure 728 arediagrammatically illustrated in FIG. 8. In the embodiment of FIG. 8,springs 752 act to bias suspended motive rollers 732 against an interiorsurface 720 of flexible material 706. Springs 752 may comprise, forexample, sheet metal arms. A compression motion and an extension motionof springs 752 and suspended motive rollers 732 are illustrated witharrows in FIG. 8.

[0063] In the embodiment of FIG. 8, housing structure 730 rotatablysupports a worm gear 744. A first thread 742 of worm gear 744 engagesteeth 740 of motive roller 734. In the embodiment of FIG. 8, rotation ofworm gear 744 will cause motive roller 734 to rotate. Rotation of motiveroller 734, in turn, causes flexible material 706 to move relative tohousing structure 730.

[0064]FIG. 9 is an enlarged, partial cross-sectional view of anapparatus 800 in accordance with an additional exemplary embodiment ofthe invention. With reference to FIG. 9 it will be appreciated thatapparatus 800 comprises a bladder 804. In some embodiments of thepresent invention, bladder has a generally toroidal or ring shape.Bladder 804 comprises a flexible material 806. Flexible material 806 ofbladder 804 has an interior surface 820 and an exterior surface 822.Interior surface 820 of flexible material 806 defines an interior volume824 of bladder 804. In some embodiments of the present invention,interior volume 824 of bladder 804 contains or is filled with a fluid, agas, liquid or combination thereof. Exterior surface 822 of flexiblematerial 806 defines a central cavity 826.

[0065] The apparatus 800 shown in FIG. 9 also includes a frame 808.Frame 808 both supports and interacts with the flexible material 806 ofthe bladder 804. Frame 808 comprises a support structure 828 and ahousing structure 830. In the embodiment of FIG. 9, housing structure830 rotatably supports a stabilizing roller 836 and support structurerotatably supports a suspended stabilizing roller 838. With reference toFIG. 9, it will be appreciated that suspended stabilizing roller 838contacts the interior surface 820 of flexible material 806 of bladder804. Stabilizing roller 836 is shown contacting an exterior surface 822of flexible material 806 of bladder 804. The rotation of the rollers andthe movement of flexible material 806 are illustrated with arrows inFIG. 9.

[0066]FIG. 10 is an additional enlarged, partial cross-sectional view ofapparatus 800 shown in the previous figure. In some useful embodimentsof the present invention, suspended stabilizing roller 838 acts to biasexterior surface 822 of flexible material 806 against stabilizing roller836. In the embodiment of FIG. 10, an arm 848 of Support structure 828acts to bias suspended stabilizing roller 838 against interior surface820 of flexible material 806. A flexing motion of arm 848 is illustratedusing arrows in FIG. 10.

[0067]FIG. 11 is an enlarged, partial, cross-sectional view of anapparatus 900 in accordance with an exemplary embodiment of theinvention. Apparatus 900 comprises a housing structure 930 thatrotatably supports a worm gear 944. A stabilizing roller 936 isrotatably supported by housing structure 930. A flexible material 906 isdisposed between stabilizing roller 936 and a skid 950. Flexiblematerial 906 may form, for example, a portion of a bladder in accordancewith the present invention. With reference to FIG. 11, it will beappreciated that skid 950 contacts an interior surface 920 of flexiblematerial 906. In some useful embodiments of the present invention, skid950 acts to bias an exterior surface 922 of flexible material 906against stabilizing roller 936.

[0068]FIG. 12 is an additional enlarged, partial cross-sectional view ofapparatus 900 shown in the previous figure. Skid 950 of apparatus 900 isshown in cross section in FIG. 12. With reference to FIG. 12, it will beappreciated that skid 950 defines a depression 956. In the embodiment ofFIG. 12, depression 956 is dimensioned to receive a portion of flexiblematerial 906 and a portion of stabilizing roller 936. The rotation ofstabilizing roller 936 and the motion of flexible material 906 areillustrated with arrows in FIG. 12.

[0069]FIG. 13 is an enlarged, partial cross-sectional view of apparatus900 in accordance with an additional exemplary embodiment of the presentinvention. Apparatus 900 includes a frame 908 comprising a housingstructure 930 and a support structure 928. A stabilizing roller 936 isrotatably supported by housing structure 930. A flexible material 906 isdisposed between stabilizing roller 936 and a skid 950. With referenceto FIG. 13, it will be appreciated that skid 950 contacts an interiorsurface 920 of flexible material 906. In some useful embodiments of thepresent invention, skid 950 acts to bias exterior surface 922 offlexible material 906 against stabilizing roller 936. In the embodimentof FIG. 13, an arm 948 of support structure 928 acts to bias skid 950against interior surface of flexible material 906. A flexing motion ofarm 948 is illustrated using an arrow in FIG. 13.

[0070]FIG. 14 is a cross-sectional view of a bladder 104 in accordancewith an exemplary embodiment of the present invention. Bladder 104comprises a flexible material 106. The movement of flexible material 106is illustrated with arrows in FIG. 14. With reference to FIG. 14, anexterior portion of bladder 104 can be viewed as moving in one directionwhile an interior portion of bladder 104 is moving in the oppositedirection. The result is that the entire shape can move along itscentral axis while the external material rolls around itself. Thus, theflexible material may be described as circulating around and through theframe in a continuous motion from inside the central cavity long iscentral axis to the outside where the exterior surface of the flexiblematerial travels along in contact with the interior surface of agenerally tubular space or environment or other lumen. A traveldirection of bladder 104 is labeled TD in FIG. 14. This motion is welladapted to travel within a generally cylindrical or tubular space, evena collapsible one, such as exists with the colon or rectal canal. Theentire object moves with minimal to no slipping because its exteriorsurface remains in relatively constant or continuous contact with theinterior of the space while the interior surface of the flexiblematerials moves forward in the direction of travel as shown.

[0071]FIG. 15 is an additional cross-sectional view of bladder 104 shownin the previous figure. In the embodiment of FIG. 15, bladder 104 istraveling a in second travel direction TD that is generally opposite thetravel direction shown in the previous figure. The movement of flexiblematerial 106 of bladder 104 is illustrated with arrows in FIG. 15. Withreference to FIG. 15, an exterior portion of bladder 104 can be viewedas moving in one direction while an interior portion of bladder 104 ismoving in the opposite direction.

[0072] In some exemplary embodiments of an apparatus in accordance withthe present invention, a frame is formed of a support structure and aseries of at least two sets of interlocking rollers or skids located onthe support structure. The support structure is located within theinterior volume of the enclosed ring. The rollers or skids are locatedso as to maintain the flexible material of the enclosed ring betweenthem. To further accommodate folds and wrinkles in the flexible materialthe rollers or skids may be suspended and may apply force to theflexible material and the matching rollers or skids. Embodiments ofpossible suspension mechanisms are illustrated in the figures.

[0073] The ends of support and housing structures may be tapered forsome applications. Embodiments of the invention having tapered ends arewell-suited, but not necessary for medical applications and procedures,e.g., colonoscopy or rectal examination. However, such tapering is notnecessary for all applications, particularly those involving spaces orenvironments of large dimension. The tapered ends of the support andhousing structures may serve a number of functions, including, but notlimited to allowing the two structures to fit and work together withoutsliding apart; presenting a smooth and gradual surface to over which theflexible material travels, and easing the apparatus' throughconstrictions and its passage around curves and comers.

[0074] The series of at least two sets of interlocking rollers or skidsare located on the support and housing structures or in the case whereonly a support structure is utilized, the rollers or skids are locatedon the support structure. A set of rollers or skids may be comprised ofone or more roller, one or more skid or combination thereof located onone or more of the structures. A set may be formed of a single roller orskid, a pair of adjacent rollers or skid, a single roller or skid on onestructure and a pair comprised of two or more rollers, two or more skidsor a combination of both on the other, and other variations andcombinations of rollers and skids located in corresponding alignedposition on each structure. The rollers or skids are interlocked in twodirections, along and across the apparatus' central axis. Theinterlocking is done in such a way as to maintain a generally constantor fixed distance between the support and housing structures, so thatthey are in a generally fixed spatial relationship. As shown in thefigures, the flexible material of the enclosed ring passes between therollers or skids. This helps to prevent the toroid's flexible materialfrom being compressed between the two structures except where itinteracts with the rollers or skids. When powered, the rollers engagethe flexible material and provide a motive, directional force to theflexible material which allows the apparatus to move in a forward orbackward direction. With the exterior surface of the enclosed ringcontacting and conforming to the interior surface or surfaces of agenerally tubular space or environment, the powering of the rollersmoves the flexible material as illustrated in the figures. This movementof the flexible material provides the self-propulsion for the apparatus.

[0075] If unpowered, the rollers or skids provide a means offacilitating the motion of the flexible material between the support andhousing structures, for example when the apparatus is initially beingintroduced. When propelled, preferably, only the rollers on theadvancing side of the apparatus are powered. This will tend to keep theflexible material from wrinkling, kinking and bunching-up by pulling theflexible material through the toroid's central cavity instead of pushingit. However, the apparatus can be operated with the rearward roller(rearward relative the direction of motion) being powered or bothforward and rearward rollers being powered.

[0076] The fluid-filled toroid is also well adapted to the numerouscurves, comers and constrictions found in body cavities and lumens. Asone part of the shape is squeezed or pushed the liquid or gas isdisplaced and accommodated by the flexibility of the bladder.

[0077] The apparatus may include an accessory tube, such as a flexibletube, connected to the apparatus and leading outside the patient orother space into which it is introduced. For example, as the apparatusenters and travels within the patient, the tube remains connected and ispulled by the device. It can also be pushed or pulled as a means ofmoving the inside a patient or other space. The accessory tube can be asingle pathway or conduit or may contain multiple pathways or conduitswhich can be used to insert a variety of accessory devices into thepatient or to connect such devices to external support devices know tothose skilled in the art, including but not limited to computers,analytical or diagnostic equipment or other electronic equipmentappropriate to the given application.

[0078] Various types of accessory devices can be utilized with ormounted to the apparatus. Such accessory devices include, but are notlimited to, endoscopes, cameras, fiber optic cables, electroniccommunication cables, lasers, surgical instruments, medical instruments,diagnostic instruments, instrumentation, sensors, stent catheters, fluiddelivery devices, drug delivery devices, electronic devices, tools,sampling devices, assay devices, other accessory devices, andcombinations thereof.

[0079] The material requirements for the various components of theinvention can be fulfilled by a number of substances. For medicalapplications, all materials must possess a high degree ofbiocompatibility and be capable of withstanding sterilization methodsknow to those skilled in the art, such as radiation, steam or chemicalvapor.

[0080] The fluid located inside the enclosed ring or bladder may be aliquid, such as a light oil, water, saline solution, lubricant; a gas,such as air, nitrogen, or carbon dioxide; or a combination thereof.Preferably, for medical or veterinary application or use, the fluid willbe non-toxic. For the enclosed ring or bladder the flexible materialshould be a material with puncture, rupture and abrasion resistancecharacteristic as appropriate to the conditions of the interior surfaceof the space or environment into which the apparatus will be introduced.The flexible material may also posses a textured surface that wouldassist its motion against the surface of the lumen it traverses. Othercharacteristics to be considered in the selection of suitable materials,for example, softness, flexibility and conformability. The toroid'smaterial must also be capable of being sealed into an enclosed ring orclosed bladder by some means such as heat sealing, an adhesive or achemical bond. A variety of polymeric or plastic materials can be usedas the flexible material.

[0081] The support and housing structures may be formed of either asemi-flexible or semi- rigid material such as a polymer or a rigidmaterial, such as stainless steel, a composite material or combinationsthereof. The rollers or skids will require a material or group ofmaterials that is high in strength and capable of being formed into verysmall parts. The roller material must also provide a sufficiently highdegree of friction (not slip) against the flexible material withoutdamaging it while the skids must provide a sufficiently low degree offriction (slip) against the flexible material without damaging it. Thesurfaces of the support and housing structures may be comprised of oneor more materials that reduce or eliminate friction caused by the motionof the flexible material across the surfaces of the support and housingstructures.

[0082] For applications of a non-medical nature, the materials requiredmust retain most properties described above but do not necessarilyrequire biocompatibility or sterilization tolerance. The materials usedfor the invention in non-medical applications will require sufficientdurability and compatibility to suit the environment in which they areto be used.

[0083] Though a number of applications and uses of the apparatus of theinvention have been identified herein above, additional applications anduses include, but are not limited to, inspection of difficult to reachpipes, tubes and caverns by carrying a camera or other optical,electrical or mechanical inspection device; transporting remotelycontrolled tools for use in difficult to reach locations; routing orpulling cable, wires rope, etc. through long narrow passages; pushing orpulling material through a pipe by taking advantage of the invention'sability to conform to the shape of its environment allowing it toprovide a seal between the spaces on either side, i.e. the inventioncould facilitate emptying a pipe of material without mixing it with airor other material on the other side of the invention. Many of theseapplications would work equally well if the device was self-propelled orsimply pushed or pulled from the outside.

[0084] While exemplary embodiments of this invention and methods ofpracticing the same have been illustrated and described, it should beunderstood that various changes, adaptations, and modifications might bemade therein without departing from the spirit of the invention and thescope of the appended claims.

1. A propulsion apparatus for transport of accessory devices within body cavities or canals, sections of pipe, lumens, and other generally tubular spaces and environments, comprising: a toroid, the toroid being a fluid-filled, enclosed ring formed of a flexible material, the enclosed ring defining a central cavity, having an interior volume and presenting an exterior surface and an interior surface which move continuously in opposite directions when the apparatus is in motion; a frame formed of a support structure located within the interior volume of the enclosed ring, a housing structure concentrically and coaxially located relative to the Support structure and disposed in the central cavity of the enclosed ring; and a series of at least two sets of interlocking rollers or skids located on the Support and housing structures, the rollers or skids being located so as to maintain the two structures in a fixed spatial relationship with the flexible material of the enclosed ring being positioned between the two structures and the rollers or skids located thereon.
 2. The apparatus of claim 1, further comprising at least one accessory device.
 3. The apparatus of claim 1, further comprising a power source connected to the rollers which when powered provide a motive force to the flexible material of the enclosed ring.
 4. The apparatus of claim 3, wherein the power source is an external power source.
 5. The apparatus of claim 3, wherein the power source is an internal power source.
 6. The apparatus of claim 1, wherein the flexible material is a polymeric material.
 7. The apparatus of claim 1, further comprising a power source for powering the rollers, and at least one accessory device.
 8. The apparatus of claim 1, further comprising an accessory tube, the tube having at least one pathway through which accessory devices can be inserted or connected to external supporting devices.
 9. The apparatus of any one of claims 2, 7 or 8, wherein the at least one accessory device is selected from the group consisting of endoscopes, cameras, fiber optic cables, electronic communication cables, lasers, surgical instruments, medical instruments, diagnostic instruments, instrumentation, sensors, stent catheters, fluid delivery devices, drug delivery devices, electronic devices, tools, sampling devices, assay devices, other accessory devices, and combinations thereof.
 10. The apparatus of claim 1, further comprising a worm gear.
 11. The apparatus of claim 1, wherein at least one of the rollers is suspended by a spring.
 12. The apparatus of claim 1, wherein at least one of the rollers is rotatably supported by an arm.
 13. A propulsion apparatus for transport of accessory devices, comprising: a toroid, the toroid being a fluid-filled, enclosed ring formed of a flexible material, the enclosed ring defining a central cavity, having an interior volume and presenting an exterior surface and an interior surface which move continuously in opposite directions when the apparatus is powered; a frame formed of a support structure located within the interior volume of the enclosed ring, a housing structure concentrically and coaxially located relative to the support structure and disposed in the central cavity of the enclosed ring; a series of at least two sets of interlocking rollers or skids located on the support and housing structures, the rollers or skids being located so as to maintain the two structures in a fixed spatial relationship with the flexible material of the enclosed ring being positioned between the two structures and the rollers or skids located thereon; an accessory tube, the tube having at least one pathway through which accessory devices can be inserted or connected to external supporting devices; at least one accessory device inserted through the accessory tube or connected through the accessory tube to at least one external supporting device; and a power source connected to the rollers which when the apparatus is powered provide a motive, directional force to the flexible material.
 14. A propulsion apparatus for transport of accessory devices, comprising: a toroid, the toroid being a fluid-filled, enclosed ring formed of a flexible material, the enclosed ring defining a central cavity and having an interior volume, a powered frame formed of a support structure located within the interior volume of the enclosed ring, a housing structure concentrically and coaxially located relative to the support structure and disposed within the central cavity of the enclosed ring, a series of at least two sets of interlocking rollers or skids located on the support and housing structures, the rollers or skids being located so as to maintain the two structures in a fixed spatial relationship with the flexible material of the enclosed ring being positioned between the two structures and the rollers or skids located thereon, the rollers being connected to a power source and when powered providing a motive, directional force to the flexible material.
 15. An endoscopic, medical procedure; comprising the steps of: introducing a self-propellable, endoscopic apparatus into the rectum and anal canal of a patient, the apparatus being equipped with at least one accessory device and connected to at least one external support device; powering the apparatus to propel the apparatus forward through the anal canal and into the colon up to a location in the colon at which at least one medical procedure is to be performed; performing the at least one medical procedure with the at least one accessory device, optionally, serially propelling the apparatus to another location in the colon at which the at least one medical procedure is to be performed and performing said at least one medical procedure; propelling the apparatus backward through the colon and into the anal canal; and removing the apparatus from the patient.
 16. An endoscopic, medical procedure; comprising the steps of: introducing a self-propellable, endoscopic apparatus into the rectum and anal canal of a patient, the self-propellable endoscopic apparatus comprising: a toroid, the toroid being a fluid-filled, enclosed ring formed of a flexible material, the enclosed ring defining a central cavity and having an interior volume; a powered frame formed of a support structure located within the interior volume of the enclosed ring, a housing structure concentrically and coaxially located relative to the Support structure and disposed within the central cavity of the enclosed ring, a series of at least two sets of interlocking rollers or skids located on the support and housing structures, the rollers or skids being located so as to maintain the two structures in a fixed spatial relationship with the flexible material of the enclosed ring being positioned between the two structures and the rollers or skids located thereon, the rollers being connected to a power source and when powered providing a motive, directional force to the flexible material; and at least one accessory device and connected to at least one external support device; powering the apparatus to propel the apparatus forward through the anal canal and into the colon up to a location in the colon at which at least one medical procedure is to be performed; performing the at least one medical procedure with the at least one accessory device; optionally, serially propelling the apparatus to another location in the colon at which the at least one medical procedure is to be performed and performing said at least one medical procedure; propelling the apparatus backward through the colon and into the anal canal; and removing the apparatus from the patient.
 17. An endoscopic procedure; comprising the steps of: introducing a self-propellable, endoscopic apparatus into the generally tubular space or environment, the apparatus being equipped with at least one accessory device and connected to at least one external support device; powering the apparatus to propel and navigate the apparatus forward in the tubular space to a location at which at least one endoscopic procedure is to be performed; performing the at least one endoscopic procedure with the at least one accessory device; optionally, serially propelling the apparatus to another location in the tubular space at which the at least one endoscopic procedure is to be performed and performing said at least one endoscopic procedure; propelling the apparatus backward through tubular space; and removing the apparatus from the tubular space. 